Platefin-type heat exchanger and method of making same



Dec. 20, 1966 KEllCHl KIMURA PLATEFIN-TYPE HEAT EXCHANGER AND METHOD OF MAKING SAME 5 Sheets-Sheet 1 Filed July '7, 1964 INVENTOR.

BY Keiichi Kimura nu g1. MJ'IH-W AYTQRNEY Dec. 20, 1966 KEIICHI KIMURA PLATEFIN-TYPE HEAT EXGHANGER AND METHOD OF MAKING SAME Filed July 7 1964 5 Sheets-Sheet 2 INVENTOR.

BY Ke ii chi Kimura Dec. 20, 1966 KEllCHl KIMURA 3,

PLATEFIN-TYPE HEAT EXCHANGER AND METHOD OF MAKING SAME 5 SheetsSheet 5 Filed July 7, 1964 R s I m M 5 8 .6 q M 6 6 6 W M Fl" w G 6 e mw Q Y M 3/ w.

Ilium I mm munlmumm Dec. 20, 1966 KEllCHl KIMURA PLATEFIN-TYPE HEAT EXCHANGER AND METHOD OF MAKING SAME Filed July 7, 1964 5 Sheets-Sheet 4 INVENTOR.

BY Keiichi Kimura Dec. 20, 1966 KEllCHl KIMURA 3,292,639

PLATEFIN-TYPE HEAT EXCHANGER AND METHOD OF MAKING SAME Filed July '7, 1964 5 Sheets-Sheet 5 INVENTOR.

BY Keii chi Kimura A Tread v United States Patent 3,292,689 PLATEFlN-TYPE HEAT EXCHANGER AND METHOD OF MAKING SAME Keiichi Kimura, Yao-shi, Osaka-fu, Japan, assignor to Kimnrakoki Co., Ltd., Osaka, Japan Filed July 7, 1964, Ser. No. 380,776 Claims. (Cl. 165-151) This invention relates to the method of manufacturing plate fin-type heat exchangers. More particularly, the invention pertains to a heat exchanger of the type having a plurality of spaced parallel plate fins mounted on a plurality of fluid conduit tubes or pipes.

It is one object of the present invention to provide a heat exchanger having a maximum heat exchanging area.

Another object of the invention is to provide a heat exchanger having the fluid conduit tubes mounted in the openings of the plate fins, which openings are smaller in diameter than the fluid conduit tubes.

A further object of the invention is to provide a heat exchanger having annular flanges or walls as heat transfer areas, said flanges being formed when the fluid conduit tubes are mounted in the openings of the fin plates.

A still further object of the invention is to provide a heat exchanger of the above character which is easy and simple in construction and yet remarkably eflicient in operation and inexpensive of manufacture.

Other objects and specific features of the invention will become apparent in view of the following:

According to the principles of the present invention, the above objects and specific features are accomplished by mounting the fin plates on the fluid conduit tubes or pipes in such a manner that said fluid conduit tubes are tightly engaged in position by means of the flanges which are formed around the body of the tubes during the course of said mounting operation.

In more detail, there are provided, in each of the plates to be employed as fins constituting the heat exchange core of the present invention, a plurality of openings, each of which is smaller in diameter than the fluid conduit tubes to be mounted therein. There are further provided on each of said plates a plurality of folding lines or cuts, each of which is concentric with said openings and has a diameter substantially equal to that of the fluid conduit tubes.

Each of the plates thus prepared is engaged one by one with the fluid conduit tubes by mounting in such a manner that each of the peripheral portions of the openings is forced by the driving force applied to the plate to turn upward along the line demarcated by the folding cuts, whereby there is formed a cylindrical flange around each of the bodies of the fluid conduit tubes, tightly engaging in position said tubes and forming a maximum heat transfer area.

A fuller understanding of the present invention may be made by referring to the following description of some preferred typical embodiments of the principles of the present invention illustrated in the accompanying drawin gs, in which:

FIG. 1 is a front view, partly removed, of a heat exchanger embodying the principles of the invention;

FIG. 2 is a side elevation view of FIGURE 1, rotated 90; 7

FIG. 3 is a magnified perspective view of a plate, partly removed, to be employed as a fin constituting the heat exchanger of FIGURE 1;

FIG. 4 is a magnified perspective view, partly removed, showing a manner of mounting the plate on a fluid conduit tube;

FIG. 5 is a schematic front view showing theassembly line embodying the principles of the invention;

FIG. 6 is a magnified front view, partly removed and partly in section of the forming press employed in the assembly line shown in FIGURE 5;

FIG. 7 is a side elevation, partly removed and partly in section, showing a mode of mounting the plates on the fluid conduit tubes;

FIG. 8 is an enlarged cross sectional view taken along the line AA of FIGURE 7;

FIG. 9 and 10 are schematic front views illustrating the mode of mounting a plate fin on a fluid conduit pipe respectively.

FIG. 11 is a schematic diagram showing an electric circuit connecting the integral parts of the assembly line of FIGURE 5;

FIGURES 12 and 13 are'magnified sectional views, partly removed, showing modified modes of mounting a plate on a fluid conduit tube in line with the principles of the invention.

Referring now to the drawings, there is shown in FIG- URE 1 a heat exchanger of the present invention having spaced heat conductive fins 21 transversely mounted on spaced parallel fluid conduit tubes 20 with one end 22 serving as a fluid intake member and the other end 23 as a fluid outlet member, said fluid conduit tubes 20 being further connected with one another by means of end connections 24.

What is inventive in this connection is the mode of mounting the cooling fins 21 on the fluid conduit tubes 20. According to the principles of the invention, there is provided in a plate 30 to be employed as a fin a plurality of openings 31 having an internal diameter smaller than the external diameter of the fluid conduit tubes 20 to be mounted therein, said openings being formed at predetermined spaced interval by means of a forming press 40 as shown in FIGS. 3, 5 and 6.

There is further provided on said plate 30 a plurality of annular folding lines or cuts 33, each of which is concentric with a respective one of said openings 31 and has an internal diameter substantially equal to the external diameter of the fluid conduit tubes 20, said annular cuts 33 being formed by means of said forming press 40 simultaneously with the forming of openings 31 so as to provide an annular portion or section 35 surrounding the openings 31. Each of the plates 30 thus prepared is then engaged one by one with the fluid conduit tubes 20 by mounting in such a manner that each of the annular portions 35 is forced by the longitudinal driving force ap-- plied to the plate 30 to turn upward along the folding lines 33, whereby there are formed upturned cylindrical flanges 36, as shown in FIG. 4, around each of the bodies of the fluid conduit tubes 20, tightly engaging said tubes in position and forming a maximum heat transfer area.

In FIGURE 5 is shown the assembly line employed in association with the present invention, mainly consisting of sheet plate supply roll 37, forming press 40 and mounting device 41. The sheet plate 30 is first supplied to the forming press 40 by means of feed rolls 38 to be punched and demarcated with folding cuts in accordance with the principles of this invention, and the sheet plate thus prepared is fed into the mounting device 41 by means of feed rolls 39, guide roll 94, and other guide rolls 83 and 84 serving as a means to prevent lateral displacement of said sheet plate. Then the sheet plate driving table 52 (FIG. 7) constituting the mounting device 41 is energized to drive downward the punched sheet plate, whereby the sheet is cut into given size and shape, and mounted on the fluid conduittubes 34 parallelly erected in position on the conduit tube support 69.

The forming press 40 employed in the present invention is shown in FIGURE 6, mainly comprising a bed 42 having a plurality of dies 44, and a movable frame 43 having Patented Dec. 20, 1966 a plurality of punches 45 in a position facing said dies 44, said dies 44 being spaced at predetermined distances in accordance with the desired arrangement or construction of the fluid conduit tubes 34 constituting the heat exchanger of the present invention. Members 46 are folding line cutters, each of which is provided with an inturned top flange 46a which is, when idle, movably pressed by a helical spring 47 onto the shoulder 48 of the punch holder 45a. Said dies 44, punches 45 and folding line cutters 46 are of a size predetermined in association with the desired construction of the heat exchanger of this invention.

The construction of the mounting device 41 is shown in FIGURE 7, mainly comprising plate driving frame 50, fluid conduit support 69 and driving motor 65. In more detail, there is secured to one end of said plate driving frame 50 a plate driving table 52 by means of a bolt 53. At right angle to said plate driving table 52 and passing therethrough, there are erected spaced parallel cylindrical guides 95 for passing therethrough fluid conduit tubes 34. Plate guide members 83 and 84 are provided underneath plate driving frame 50.

The plate driving frame 50 is further adapted to make a reciprocal movement, upward and downward, along guide shafts 51 by means of a rack 54 which is disposed substantially parallel to said guide shafts 51 and is associated via pinion 55 with a segment gear 56 which is adapted to be oscillated by integral lever 58 aboutfulcrum 57. Lever 58 is pivotally connected by pin 60 with a link 59 having one end movably and selectively connected by means of a bolt 64 to one of the openings 63 spaced at predetermined distances along the peripheral portion of the pulley 62; Pulley 62 is fixed to a shaft 61 and is driven by the shaft of the driving motor 65 via reduction belt 67, magnetic control clutch 66 and another reduction belt 68.

Member 69 is a fluid conduit tube support which is threadedly engaged with a screw shaft 70, the downward longitudinal movement of said support 69 being controlled by a guide shaft (not shown) extending at right angles to support 69. Screw shaft 70 is connected with a spline shaft 73 by means of gears 71 and 72. Another spline shaft 74 in which is positioned in parallel to spline shaft 73, is connected with the pulley shaft 61 via gears 75 and 76, spindle 77, bevel gears 78 and 79, and belt 80. Gears 81 and 82 are replaceably engaged with said spline shafts 73 and 74 and so adapted as to selectively control the transmission ratio of the movement of the pulley 62. A changeover switch 85 is operated when the plate driving frame 50 reaches the upper limit of its reciprocal movement or stroke, and another change-over switch 86 is operated when the forward end of the punched plate comes into contact therewith. Plate cutters 91 and 92 are shown in FIG. 5. Cutter 91 is fixed to one end of the plate driving frame 50 and the other cutter 92 is fixed to the top end portion of the supporter 93 in a position facing said cutter, 91. r

In FIGURE 11 is shown a mode of electrical connection of the present embodiment. Transfer rolls 38.and 39 are connected in parallel with each other in association with the power source 87 via the contact 86b of the change-over switch 86, said contact 86b being normally closed by means of a spring. The forming press 40 and the electromagnetic control clutch 66 are also joined in parallel in association with the power source 87 via the contact 86a of the change-over switch 86, said contact 86a being normally open by means of a spring. Circuit 88 is a maintenance circuit of the contacting point 86a including parallel change-over switches 49 and 85 which are normally closed by a spring respectively. At 90 is indicated a hand switch.

The assembly line thus constructed operates in the following manners:

Fluid conduit tubes 34 are erected on the fluid conduit tube support 69 in complete agreement with the spacing of the dies 44 and punches 45 of the forming press 40, each of the top ends of said fluid conduit tubes 34 being protected with a tapered cap 89. When the hand switch 90 is closed, the transfer rolls 38 and 39 are energized to feed, at a predetermined constant velocity, the punched portion of the plate 30 into the plate driving frame via guide roll 94 and supporter 93 and then guide rolls 83 and 84. Incidentally the initial portion of said plate 30 is punched by operating the punch forming press 40 by hand. When the forward end of said plate 30 abuts against the change-over switch 86, the switch 86 closes the contact 86a and opens the contact 86b, interrupting the transferringv operation of the transfer rolls 38 and 39, and allowing the forming press 40 to make punching operation by one stroke via the electromagnetic control clutch 66. During the operation of said stroke, the electromagnetic control clutch 66 also operates so that the rotating movement of the driving motor 65 is transmitted to the screw shaft 70 via pulley 62, belt 80, bevel gears 79 and 78, shaft 77, and gears 76, 75, 82, 81, 72 and 71 to adjust the position of the fluid conduit tube support 69.

The rotating movement of the driving motor 65, on the other hand, is transferred to the plate driving frame 50 via pulley 62, link 59, lever 58, segment gear 56, pinion 55 and rack 54, allowing the frame 50 to make a downward.

drive, whereby the punched portion of the plate 30 is cut into a desired size by means of cutters 91, and 92 and the portion thus cut away is further driven downward until said cu-t plate is mounted as a fin at the predetermined space intervals on the fluid conduit tubes 34, allowing the caps 89 and the bodies of said tubes 34 to pass through the openings of said cut plate and into the cylindrical guide shafts 95, whereby the plate is tightly engaged as a fin with the bodies of the fluid conduit tubes 34 in such a manner as shown in FIGURE 4 by means of cylindrical flanges formed by the peripheral portions surrounding the openings 31, which portions are forced to turn upward by the driving force applied to the plate.

When the sheet plate driving table 52 reaches the lowest limit of its drive, the motion of frame 50 is reversed so that it moves upwardly, releasing the fin 30 from the contact with the change-over switch 86, whereas both of contacts 86a and 86b are maintained at the former operating position by means of the maintenance circuit 88 until the plate driving frame 50 reaches the upper limit of its reciprocal movement. At the same time, the fluid conduit tube support 69 and accordingly the fluid conduit tubes 34 are gradually shifted downward by the constant rotating action of the screw shaft 70, and the sheet plate 30 fed into the forming press 40 is punched and det marcated with folding lines by means of dies 44, punches 45' and folding line cutters 46 provide the plate with concentric openings and folding lines for mounting therein fluid conduit tubes 34, the groove cutter 46 being so adapted as not to cut through the plate in association with the helical spring 47. When the pressing operation of the forming press 40 is finished and the plate driving frame 50 reaches the upper limit of its reciprocal movement, the change-over switches 49 and operate again to release the contacts 86a and to close the contact 86b so as to convert the entire system to the next stroke of mounting operation, wherein the transfer rolls 38 and 39 are again energized to feed a fresh portion of the plate 30 into the forming press 40 the punched portion of the plate 30 into the plate driving frame 50. When the forward end of the punched portion of the plate 30 thus comes into contact with the changeover switch 86, said switch operates again to start a second mounting operation as described hereinbefore.

The fin mounted on the fluid tubes 34 by said second mounting operation, however, is spaced a distance higher than the first fin mounted by the first mounting operation, because the position of the fluid conduit tu'be suppont 69 and according that of the fluid conduit tubes 34 are shifted downward at a synchronized ratio by the constant rotating movement of the screw shaft 70. The desired heat exchanger shown in FIGURE 1 is thus obtained by repeating said punching and mounting operations stroke by stroke. Namely, upon completion of the mounting operation, the resultant fabric is removed from the support 69 by manually opening the switch 90, and subjected to further finishing treatments, such as taking off the tapered caps 89, associating the conduit tubes 34 by means of connecting pipes, and the like. The empty support 69 is restored to the starting position by a reversible means, not shown. The spacing ratio of the fins can be varied by changing the rotating velocity of the screw shaft 70 by replacing the gears 81 and 82 with new ones having the desired gearing ratio.

In view of the foregoing, it may be apparent that the plate fin-type heat exchanger of the present invention can be constructed in an easy and a simple manner with markedly improved heat exchanging efliciency. For the major principle of this invention comprises merely mounting heat conductive tubes in the openings provided inthe plates, each of said openings being further provided with a concentric peripheral portion which is demarcated with a folding line or cut substantially equal in diameter'with the body of the conductive tu'bes, so that there is erected in tight engagement with each of the conductive tubes an annular flange which is integral not only with the resultant plate fin but substantially with the body of the conductive tubes.

According to the principles of the invention, it is most profitable to carry out the folding line demarcating, punching and mounting operations on an assembly line as shown hereinbefore.

But these operations may also be performed by hand either one by one or in combination as the case may permit.

Furthermore, folding lines 33 may be formed either on the top surface of the plate as shown in FIG. 4 or on the bottom surface of the plate as shown in FIG. 12 at 100. In the latter case, particularly, it is possible to connect the plate and fluid conduit tubes with less amount of force than in the former case. Alternatively, said folding lines 33 may be formed on both surfaces of the plate as shown in FIG. 13 at 111 and 112, in which case the connection of the plate and fluid conduit tubes can be effected with minimum amount of force.

Instead of the annular folding cuts employed in the present invention, there may further be employed shaped folding cuts with the same improved effects as described hereinbefore.

While the present invention has been shown and described in association with the preferred embodiments herein-before it is to be understood that the same i not so limited but shall cover and include any and all modifications of the invention which fall within the scope thereof.

I claim:

1. A plate-fin heat exchanger comprising, in combination, a plurality of spaced, substantially parallel, heat exchanging plate-fins mounted on plural substantially parallel fluid conduit tubes; each tube extending through a respective opening in each plate-fin and being tightly embraced by a one-piece cylindrical flange which encircles the tube and extends from the surface of each plate concentric with the respective opening; each cylindrial flange extending from a circular depression in at least one surface of the associated plate, the circular depression being concentric with the associated opening and having a diameter substantially equal to the outer diameter of the tube extending through the associated opening.

2. A method of constructing a plate-fin heat exchanger of the type having plural spaced substantially parallel heat exchanging plate-fins mounted on plural substantially parallel fluid conduits, said method comprising the steps of forming plural openings in the plates to be used as fins, each opening having a diameter of appreciably less than that of the fluid conduit to be extended therethrough; forming, in at least one surface of each plate, plural circular depressions each concentric with a respective opening and each having a diameter substantially equal to the outside diameter of a fluid conduit to be extended through the associated opening, whereby to demarcate, between the periphery of each opening and the associated depression, an annular zone of the associated plate; and forcing fluid conduits through said plates in substantially coaxial alignment with each opening to deform said annular zones out of the planes of the plates to form substantially cylindrical flanges tightly engaging the tubes extending through the associated openings.

3. The method of constructing a plate fin heat exchanger as claimed in claim 2, wherein said depressions are formed in one surface of the plates and the fluid conduit tubes are mounted into the openings from said one surface.

4. The method of constructing a plate fin heat exchanger as claimed in claim 2, wherein said depressions are formed in one surface of the plates and the fluid conduit tubes are mounted into the openings from the op posite surface.

5. The method of constructing a plate fin heat exchanger as claimed in claim 2, wherein said depressions are formed in both surfaces of the plates and the fluid conduit tubes are mounted into the openings from one of said surfaces.

References Cited by the Examiner UNITED STATES PATENTS 2,189,652 2/1940 Lehman l5l X 2,482,595 9/1949 Plum 165--182 2,602,650 7/1952 Marcotte 165151 X 3,190,353 6/1965 Storfer 165--l82 ROBERT A. OLEARY, Primary Examiner.

N. R. WILSON, Assistant Examiner. 

1. A PLATE-FIN HEAT EXCHANGER COMPRISING, IN COMBINATION, A PLURALITY OF SAPCED, SUBSTANTIALLY PARALLEL, HEAT EXCHANGING PLATE-FINS MOUNTED ON PLURAL SUBSTANTIALLY PARALLEL FLUID CONDIUT TUBES; EACH TUBE EXTENDING THROUGH A RESPCTIVE OPENING IN EAH PLATE-FIN AND BEING TIGHTLY EMBRACED BY A ONE-PIECE CYLINDRICAL FLANGE WHICH ENCIRCLES THE TUBE AND EXTENDS FROM THE SURFACE OF EACH PLATE CONCENTRIC WITH THE RESPECTIVE OPENING; EACH CYLINDRIAL FLANGE EXTENDING FROM A CUIRCULAR DEPRSSION IN AT LEAST ONE SURFACE OF THE ASSOCIATED PLATE, THE CIRCULAR DE- 